Resuscitator



H SEELER RESUSCITATOR June 29, 1954 Origihal Filed Feb. 26, 1951 I5Sheets-Sheet 2 7'0 665 SOURCE To rec: MESA INVEN TOR. HENAEY 555156 H.SEELER RESUSCITATOR June 29, 1954 3 SheetsSheet 3 M m w w r 0 5 new f mM a P\ V 2 A O 3 nwU a I M w 3 6 K VH V m 3 U, m 7 a m m m 1 5 5 m w M.1 5 w r H E z |Y B 6 ll L 222 Z a, P M 5 6 m m w MM m a r I. T 6 E E gM H J mw INVENTOR. HENEY JEELEE as PATENT OFFICE BESUSCITATOR HenrySeeler, Dayton, Ohio Original No.

2,581A50, dated January 8, 1952, Se-

rial No. 212,818, February 26, 1951. Reissue No. 23,496, dated May 20,1952, Serial No. 271,841, February 15, 1952. This application forreissue May 26, 1953, Serial No. 357,653

(Granted under Title 35, U. s. Code (1952).

- sec. 266) 19 Claims.

Matter enclosed in heavy brackets the first and this reissuespecification; the first reissue; matter printed made by this reissue.

The invention described herein may be manufactured and used by or forthe United States Government ior governmental purposes without paymentto me of any royalty thereon.

The present invention relates to a resuscitator or artificialrespiration device of simple, compact and reliable construction.

The primaryobject of the invention is to provide a resuscitator of thekind which includes an aspire-tor into which flows a gas under pressuresuitable for use in resuscitating human patients and wherein a crankactuated butterfly valve within the aspirator is automatically movedfrom an open position to a closed position and vice verse. by the actionof a pressure responsive means coupled to an overcenter spring meansassociated with the crank actuated valve, whereby the valve when openallows gas to flow through the aspirator to produce a suction eflect andwhen closed causes gas to flow laterally from the aspirator to produce apressure effect.

A further object of the invention is to provide a resuscitator of thekind which includes an aspirator or Venturi tube into which flows a. gasunder pressure suitable for use in resuscitating human patients, whereina butterfly valve in the -aspirator downstream from a lateral openingtherein is rigidly connected to a simple crank operating means, whereina coil spring connected to the crank operating means is actuated by aslidably mounted rod fixed 'to a diaphragm, wherein adjustablecompression springs are provided at opposite ends of the slidablymounted diaphragm actuated rod and wherein a. gas flow channel in theresuscitator is in communication with the lateral opening in theaspirator, with a tube leading to a face mask and with one side of therod-actuating diaphragm, whereby the butterfly valve when brought toopen position by thediaphragm and slidably mounted rod acting throughthe coil spring and crank operating means functions to produce theexhalation phase of the resuscitation cycle and when brought to closedposition functions to produce the inhalation phase of the resuscitationcycle.

Another objector the invention is to provide a resuscitator systemincluding a face mask and associated resuscitator which receives itssupply of gas from a pressurized oxygen source or from a blower operatedby an impulse turbine, and wherein the turbine operates by the inflow ofatmospheric air by virtue of negative back pressure on the turbineachieved by use of a simple Jet pump operable by a water tap. 4

[1 appears in the original patent but forms no part of matter printed initalics indicates the additions made by in bold face (except referencefigures) indicates the additions Another object of the invention is toprovide a resuscitator of the kind which includes an aspirator orVenturi tube into which flows a gas under pressure and including acontrol valve in the aspirator located downstream from a lateral openingtherein and wherein the control valve is operable automatically by asimple and reliable mechanism actuated by a pressure responsivediaphragm.

The above and other objects of the invention will become apparent uponreading the following detailed description in conjunction with theaccompanying drawings, in which:

Fig. 1 is a top plan view of the present resuscitator looking down onthe gas lead-in connection and regulating means associated therewith.

Fig. 2 is a vertical cross sectional view taken on the line 2--2 of Fig.3.

Fig. 3 is a transverse cross sectional view through the resuscitator andshowing the aspirator in longitudinal cross section.

Fig. 4 is a longitudinal cross section.. taken through the aspirator andassociated control 4 valve.

Fig. 5 is a schematic view of resuscitator and associated componentscomprising a possible system for general use in hospitals, aid stationsand related installations.

RESUSCITATOR CONSTRUCTION Referring to Figs. 1 to 4 of the drawings theresuscitator will be described in detail. The main body i is ofgenerally cylindrical shape and is closed at one end by a screw threadedcap or cover plate 2 having small openings 3 therein. An annularshoulder within the body provides a seat for a circular wall member 4, acircular diaphragm I and a circular gasket 6 in series and theseelements are retained by the screw cap 2. The wall member 4 includes acylindrical extension I having its rim edge seated in a shallow grooveformed in the body i at 8. Outwardly of the extension I the wall member4 is pierced by a series of openings 9. A small cylindrical boss ill atthe center of the wall member 4 provides a guide for a slidable valveactuating rod or stem l2 extending through the center of the diaphragmand rigidly fixed to a pair of diaphragm supporting plates or disks II.At oppodte ends of the rod I! are similar compression springs l4 and iito provide light resistance to endwise movement of the rod II. Theadjust- 3 ing means for the springs II and It are identical, so thatonly one such adjusting means need be described. Adiacent to the springII the screw cap 2 is provided with a cup-like extension I,

having opposite slots l1 extending through a substantial part of thecircumference and receiving a transverse pin II, the oppomte ends ofwhich are anchored in a rotatable knob I! litting over the extension orboss ll. Ball detents 2|! in the'walls of the knob-bear on screw cap 2to give frictional adjusting action to the knob as the detents snap intosuitable indentations. Slidably mounted in the hollow extension II is. aspring abut'ment member 2| having opposite and similar cam portions 22which cooperate with transverse pin ll so as and outward movement of thespring abutment member as the knob II is rotated. As seen in Figs. land2 the knob l9 carries a pointer II which may be set with respect tosuitable indicia to indicate the pressure response of the resuscitatoras it cycles back and forth between suction and pressure phases of theresuscitation cycle. A suitable pin or other spline element 23 may beprovided to maintain the abutment member 2| in non-rotatable relationwith respect to hollow extension or boss II. The compressiveeffect ofspring I 5 determines the maximum positlve pressure applied to thepatient during the inhalation phase of the resuscitation cycle, whilethe compressive eflect of spring it determines the minimum negativepressure which obtains in the exhalation phase of the cycle. Suggestedpressure ranges for these phases are 0 to +8 inches of water for theinhalation phase and 0 to 3 inches of water for the exhalation phase.Suitable indicia adjacent to the spring adjusting knobs provide acalibrated scale for them pressure ranges. The

01' the gas reaching the fitting 2| will usually be held to the maximumpositive pressure used in to produce inward nite gas channel maximuminlet pressure resuscitation, for example about +10 inches or water.

Referring to Figs. 3 and 4, there is shown an aspirator assembly whichextends through the main body I at one side of a central location andcoaxial with respect to the gas inlet fitting 26 and a gas outlet ordischarge passage 21. The aspirator includes a tube 28 having an annularflange 28 at the inlet end seated against an annular shoulder in theresuscltator body I. Seated on the flange 29 is a flanged nozzle element32 and the contacting flanges are held in place as shown by a threadedring ll which includes wrench-receiving radial slots. The interior ofthe tubular member 28 is of flared cross section to provide a diifusersection in the asplrator extending almost to the outlet of nozzle ll.Laterally opening gas ports 32 in the tube 28 adjacent to the outlet ofnozzle provide communication to the interior of body I and particularlyto an annular space between the wall member I and the end wall of body Iremote from the diaphram 5 (see Fig. 2). A butterfly valve 33 in thetube 28 is rigidly connected to a crankshaft 34 having an oifset endsituated at one side of the rod l2 and connected thereto by an actuatingspring 85. As the rod I2 is shuttled back and forth by action of thediaphragm I, the spring 35 moves from one side to the other of the axisof rotation of crankshaft ll thus causing the valve 33 to snap to openor closed posi-v tion with a sudden movement (see Fig. 2). The solidline positions of the spring, crankshaft and bular fitting 38.

face mask.

'44 adapted groove in fltting 2t 4 valve correspond to the open positionof the valve wherein the aspirator 2| is effective to pull a vacuum inthe annular space leading to the tu- This brings about the exhalationphase of the resuscitation cycle, since the fitting it normally carriesa tube-leading to the When the valve II moves-to closed position, thegas from nozzle it can only spill out through ports 32 to providepositive gas flow through fitting II to the face mask. The annular wallportion I provides means to form a deflfrom the ports 32 to the fitting36 and vice ve This protects the moving parts, such as stem I2, springI! and crankshaft 24 from moisture exhaled from the patients lungs. Oneobjection to moisture as it relates to moving parts is the danger offreezing up at low temperatures. The operation will be more fullydescribed below.

The outlet end of tube 2. extends into a flanged tubular element 31having removable liner II which carries a screen 38 across the outer endto prevent foreign bodies and extraneous material, such as packing, fromentering the. resuscitator. The fltting 2| for connection with a sourceof gas under pressure, such as a cylinder of oxygen, has mounted thereina flow regulating valve comprising a transverse rod ll extending intolongitudinal slots ll in the fltting 26 and also into similar cam slots42 in the rotatable collar ll. The rod ll carria a tapered valve memberto enter the outer end of nozzle II and thus regulatethe size of theannular passage between the valve member and the nomle .opening. A

pair of screws ll threaded into the collar ll have inner ends riding ina circular ment of collar 43 but still permit free rotation thereof. Apointer 48 on the collar 41 serves to indicate by its position withrelation to the scale A ll, the flow rate through the regulating valveand into tlie nozzle 30. The suggested scale of values for the flow rateis from 0 to liters per minute. Ordinarily the valve will only be closedcompletely when the resuscitator is not in use but the wide range offlow rates will adapt the device for use on people of all ages and allpossible basic metabolic rates. Furthermore the flow rate in any givencase will determine the cycling rate of the resuscitator, since the rateof gas flow will determine how fast the patients lungs fill to capacityandhow fast the patient's lungs are emptied of gas, moisture and wasteproducts.

RESUSCTIATOR OPERATION that the setting of spring II will effectivelydetermine how low the pressure goes before the coil spring II swingstothe right past the, crank arm I4 and causes the crank arm and the valve33 to snap to the valve closing position and start the inhalation orpositive pressure phase of the resuscitation cycle. New with the valve3! closed to. prevent endwise move valve actuating diaphragm I theincoming gas will fiow from ports 32 into the resuscitator body andthence around the flow channel previously described to the outletfitting 3B. As the patients lungs fill up with fresh gas the positivepressure in the resuscitator will slowly increase to cause the diaphragmIi to move toward the left, thus moving the rod i2 and bringing theovercenter coil spring 35 to the dotted line position with the crank armBl still in the dotted line or valve closed position. Now thecompression spring ll is no longer producing any appreciable endwisepressure on the rod l2 but the positive pressure spring I5 is resistingfurther movement 01' the rod it toward the left. Thus it will be seenthat the setting of spring II will determine how high the pressure goesbefore the coil spring 35 swings past the crank arm 84 and causes thecrank arm and valve 83 to snap to the valve opening position and therebystart the exhalation or negative pressure phase of the resuscitationcycle. The spring 35 is shown in two positions, each approaching thecritical snap-over relation, with respect to the crank arm 34 (see Fig.2). The crank arm is shown in its two extreme positions, the lull lineposition being the valve open position (see Figs. 2, 3 and 4) and thedotted line position being the valve closed position. In the firstposition, the contact of the arm and wall 4 provides a definite stopaction and in the second position the contact of the valve 3: with thewalls or tube 28 provides a definite stop action. As noted previouslythe adjustable inlet valve determines the flow rate for a given subjectand also determines at the same time the cycling rate or theresuscitator. In practice a table oi! values is furnished with theresuscitator to show the desired setting of the inlet valve ior people0! various ages and more particularly for people of various sizes. Insome cases the values are varied from the normal, as for instance inapplying the resuscitator to persons who have absorbed noxious fumes.Here a higher flow rate will aid in eliminating from the blood some oithe undesirable dissolved gases. While the exhalation phase oi theresuscitation cycle will preferably proceed until there is a slightnegative pressure in the device, this practice is not alwaysrecommended. Some authorities do not recommend the use of negativepressures in resuscitation or artificial respiration because of thetendency to cause adhesion of lung" tissues and partial collapse ofbronchial tubes.

nnsoscrrs'rron SYSTEM Referring now to Fig. 5 there is shown onepossible resuscitation system or hook-up of general application. Theresuscitatior as described above is shown in exterior end view showingthe spring adjusting knob I! mounted on the screw cap 2. The fitting 36is connected to the face mask III, which is adapted to fit over themouth and nose of the patient and may be held in place by hand or bysuitable straps. At the race contacting edges or the mask there isprovided a flexible tube ll connected to the interior of the mask bymeans 01 a one-way valve l2, arranged so that the maximum pressure inthe mask will be developed in the tube II but will not leak back intothe mask.

The gas inlet fitting 28 is connected to a conduit BI connected througha shut-ofl valve 54 and pressure relief valve II to a blower I. Thelatter is provided with an air inlet screen 31 and the rotor I8 ismounted on a shaft-I0 ex-' tending into an adjacent impulse turbine unit80. The shaft ll! also includes a non-circular end portion 6| which maybe connected in an emergency to an electric motor or other power sourcein case the motive-power for the turbine fails. In normal operation theturbine 00 is operated by atmospheric air entering at the nozzle 62- andimpinging on the turbine rotor II. The flow of atmospheric air againstthe turbine wheel is brought about by connecting the turbine casing to ajet pump II or other vacuum pump. The jet pump is operated by passing-astream or water therethrough from a water tap 64 and the water afterpassing out or the pump flows into a suitable drain or sink II. Asecondsource or gas is conducted into the tube 51 by a conduit connected byway or a shut-off valve II and a reduction valve 61 to an oxygen tank orbottle 88. As will be understood the oxygen may be under very highpressure in the bottle 68 and in order to bring the pressure at theresuscitator inlet 28 down to about +10 inches of water there must beprovided an eificient reduction valve preferably mounted directly on theoutlet tube of tank or bottle 83.

The system illustrated in Fig. 5 should afi'ord reasonable safetybecause of the alternative sources of resuscitating gas. In theillustration, the source of compressed air from blower U6 is connectedto the resuscitator since the valve 54 is open at the same time thevalve 66 is closed. The pressure relief valve 55 near the blower is forthe purpose of maintaining a predetermined maximum pressure in theconduit 53, for instance about +10 inches of water. While pure oxygenhaving a minor percentage of carbon dioxide mixed therein is thepreferred gas, compressed air will always provide a satisfactorysubstitute. In some cases carbon dioxide is added continuously to theflowing oxygen from a separate bottle equipped with a metering valve.

The embodiment of the invention herein shown and described is to beregarded as illustrative only and it is to be understood that theinvention is susceptible of variations, modifications and changes withinthe scope of the appended claims.

I claim:

1. A resuscitator comprising, a housing defining a gas receivin chamber,said housing being provided with a port adapted for connection with amask, conduit means traversing said chamber, said conduit means beingfitted at one end for attachment to a source of gas under pressure andthe other end thereof defining a discharge port open to the ambientatmosphere, jet pump means within said conduit means and including anozzle and an adjacent constriction spaced downstream from the nozzle, arotatably mounted valve positioned between said constriction and saiddischarge port for opening and closing said conduit means, a crankshaftrigidly connected to said valve and extending outside of said conduitmeans, a valve actuating diaphragm in said housing communicating at oneside with said gas receivin chamber, a slidably mounted rod securedcentrally or said diaphragm, spring means extending laterally from saidrod and connected to said crankshaft, port means in said conduitupstream from said constriction and connecting with said gas receivingchamber, whereby gas flowing into said conduit will alternatcly flowthrough said port means and t0 the lungs of a patient wearing said maskor fiow through said iet pump means to the ambient atmosphere as saidvalve is closed or opened respectively by action of said diaphragm. rod.spring means and crankshait.

'2. A resuseitator comprising, a housing defining a gas receivingchamber, said housing being provided with a port adapted for connectionwith. a mask, conduit means traversing said chamber, said conduit meansbeing fitted at one end for attachment to a source of a gas underpressure and the other .end thereof defining a discharge port open tothe ambient atmosphere, Jet pump means within said conduit means andincluding a nozzle and an adjacent constriction spaced downstream fromthe nozzle, arotatably mounted valve positioned between saidconstriction and said discharge port for opening and closing saidconduit means, acrankshaft rigidly connected to said valve and includinga crank arm portion outside of said oonduit means, a valve actuatingdiaphragm in said housing communicating at one side with said gasreceiving chamber, a slidably mounted rod secured centrally of saiddiaphragm and extending at a right angle with respect to saidcrankshaft, a coil spring connected between said rod and said crank armportion and adapted to swing past said crankshaft to two oppositeovercenter positions as said rod reciprocates by action of saiddiaphragm and as said valve is moved to closed and open positions, portmeans in said conduit upstream from said constriction and connectingwith said gas receiving chamber, whereby gas flowing into said conduitwill alternately fiow through said portmeansandtothelungs ofapatient'wearing said mask or flowthrough said jet pump means to theambient atmosphere as said valve is closed or opened respectively byaction of said diaphragm, rod, spring and crankshaft.

3. A resuscitator comprisinga housing defining a gas receiving chamber,said housing being provided with a port adapted for connection with amask, conduit means traversing said chamber, said conduit means beingfitted at one end for attachment to a source of gas under pressure andthe other end thereof defining a discharge port open to the ambientatmosphere, Jet pump means within said conduit means and including anozzle and an adJacent constriction spaced downstream from the nozzle, arotatably mounted valve positioned between said constriction and saiddischarge port for opening and closing said conduit means, a valveactuating diaphragm positioned transversely oi said hous- 8. a perforatetransverse wall in said housing spaced from said diaphragm and having atubular extension enga ing one end of said housing away from saiddiaphragm, a rod slidably mounted through said transverse 'wall andextending axially through said tubular extension. means for securingsaid rod centrally of said diaphragm, a crankshaft rigidly connected tosaid valve and extending outside of said conduit 65 means within saidtubular extension, spring means connected between said rod and saidcrankshaft for actuating said valve from closed to open position andvice versa upon sliding movement of said rod in opposite directions, andport means in said conduit means upstream from said constriction andconnecting with said gas receiving chamber.

55 action of rising fining a gas receiving chamber, means provi a gasinlet into said housing, means providing a gas outlet from said housinginto the ambient atmosphere, means providing a fitting on a wall of saidhousing connecting with said chamber and adapted for connection with amask, an aspirator extending across said housing from said gas inlet tosaid gas outlet and including spill ports opening laterally from theaspirat'or into 10 said gas receiving chamber, a rotatably mounted valvein said aspirator downstream from said ports, a crankshaft rigidlyconnected to said valve and extending outside of said aspirator, aslidably mounted rod in said housing extending at a right 16 angle tosaid crankshaft, spring means extending laterally from said'rod andconnected to said crankshaft to assume overcenter positions at oppositesides of said crankshaft as said valve is moved from closed to openpositions, means 20 responsive to changes in pressure in saidchamher formoving said rod in opposite directions asthepressureinsaidchamberrisesandfalls. whereby a supply of gas flowingto said gasinlet will alternately fiow thro liih said ports and to thelungs of a patient wearing said mask or fiow through said aspirator tothe ambient atmosphere as said valve is closed or opened rupeetively.

5. A resuscitator as recited in claim 4, and

further comprising, separate adjustable spring means bearing on oppositeends of said slidably mounted rod.

6. A resuscitator comprising, a housing defining a gas receivingchamber, means providing a gas inlet into said housing, means providinga gas outlet from said housing into the ambient atmosphere, meansproviding a fitting on a wall of said housing connecting with saidchamber and adapted for connection with a face mask,

40 an aspirator extendingacross said housing from said gas inlet to saidgas outlet and including spill ports opening laterally from theaspirator into said gas receiving chamber. a movably mounted valve insaid aspirator downstream from said ports, valve operating meansconnected to said valve and extending outside oi said aspiraior, aslidably mounted rod in said housina'. means responsive to changes inpressure in said chamber for moving said rod in oppositedirectionsasthepre ureinsaidchamberrisesandfalls, spring mea connectedbetween said valve operating means d said rod to actuate said valve fromclosed to open position and vice versa as said rod is moved in oppositedirections by the and falling pressure in said chamber, and separateadjustable [spring] biasing means at opposite ends of said rod forbiasing said rod in opposite directions.

7. A resuscitator comprising, a housing delinw ing a gas receivingchamber, means providing a gas inlet into said housing, means providinga gas outlet from said housing into the ambient atmosphere, meansproviding a fitting on a wall of said housing connecting with saidchamber and adapted for connection with a face mask, an aspirutorattending across said housing from said gas inlet to said gas outlet andincluding spill Ports Opening laterally from the uspirator into said gasreceiving chamber, a movably mounted valve in said aspirator downstreamfrom said ports, valve operating means connected to said valve andextending outside of said aspirator, a Wot-ably mounted means in said 4.A resuscitator comprising, a housing dehousing, means responsive tochange: inpre'uure pressure in said chamber rises and falls, meansconnected between said valve operating means and said reciprocablymounted means to actuate said valve from closed to open position andvice versa as said reciprocably mounted mean 18 moved in oppositedirections by the action of risin and falling pressure in said chamber,and separate adjustable biasing means acting in opposition on saidreciprocably mounted means for biasing the latter means in oppositedirections.

8. A resuscitator comprising a housing defining a gas receiving chamber,means providing a fitting on a wall of said housing connecting with saidchamber and adapted for connection with a face mask, an aspiratorassembly associated with said housing, said aspirator assembly having agas inlet and a gas outlet opening into the ambient atmosphere, saidaspirator assembly having an opening forming a spill port openinglaterally into said gas receiving chamber, a movably mounted valve insaid aspirator assembly downstream from said ports, valve operatingmeans connected to said valve and extending outside of said aspiratorassembly, a reciprocably mounted means in said housing, means responsiveto changes in pressure in said chamber for moving said reciprocablymounted means in opposite directions as the pressure in said chamberrises and tails, means connected between said valve operating means andsaid reciprocably mounted means to actuate said valve from closed toopen position and vice versa as said reciprocably mounted means is movedin opposite directions by the action oi. rising and ialling pressure insaid chamber, and separate adjustable biasing means acting in oppositionon said reciprocably mounted means for biasing the latter means inopposite directions.

9. A resuscitator comprising a housing forming a gas receiving chamber,'a diaphragm extending across the chamber in the housing dividing thehousing into compartments, means for sealing the margins of thediaphragm to the walls of the housing, air intake ports for connectingone of said compartments to the ambient air, the other compartmenthaving an opening fitting on the wall oi'said housing connecting saidopening with a face mask, aspirator means associated with said housing,said aspirator means having a gas inlet and a gas outlet opening intothe ambient atmosphere, said aspirator means having an opening forming aspill port and communicating with said gas receiving chamber, a movablymounted valve in said aspire-tor means downstream from the inlet openingand the spill port, means operated by the diaphragm moving in responseto changes in pressure in said chamber i'or actuating the valve fromopen to closed position and vice versa, adjustable means accessible fromthe exterior of the housing for changing the pressure required toactuate the valve, and adiustable biasing means acting in opposition onsaid diaphragm for biasing the latter in opposite directions.

10. A resuscitator comprising a housing forming a gas receivingcompartment, a diaphragm forming one wall oi the compartment, means forsealing the margins of the diaphragm to the walls of the housing, theside of the diaphragm opposite the compartment being exposed to ambientatmospheric pressure, the compartment having openings, a fitting on thewall of said housing connecting one of said openings with a face mask,aspirator means associated with said housing, said aspirator meanshaving a gas inlet and a gas outlet opening into the ambientatmpsphere,said aspirator means having an opening forming a spill port andcommunicating with said gas receiving compartment, a movably mountedvalve in said aspirator means downstream from the inlet opening to thespill port, means operated by the diaphragm moving in response tochanges in pressure in said compartment for adjusting the valve fromopen to closed position and vice versa, means for restraining themovement of said last mentioned means preventing adjustment of the valvefrom open to closed position and vice versa until predetermined pressuredifferentials have been established between the ambient atmosphericpressure and the pressure of the gas in the compartment, and meansaccessible from the exterior of the housing for adjusting saidrestraining means so as to cause the valve to be adjusted in response topredetermined pressure differentials.

.11. A resuscitator comprising a housing forming a gas receivingcompartment, a diaphragm forming one wall of the compartment, means forsealing the margins of the diaphragm to the walls of the housing, theside of the diaphragm oppo site the compartment being exposed to ambientatmospheric pressure, the compartment having openings, a fitting on thewall of said housing connecting one of said openings with a face mask,aspirator means associated with said housing,

said aspirator means having a gas inlet and a' gas outlet opening intothe ambient atmosphere, said aspirator means having an opening forming aspill port and communicating with said gas receiving compartment, amovably mounted valve in said aspirator means downstream from the inletopening to the spill port, means operated by the diaphragm moving inresponse to changes in pressure in said compartment for adjusting thevalve from open to closed position and vice versa, means for restrainingthe movement of said last mentioned means preventing adjustment of thevalve from open to closed position and vice versa until predeterminedpressure differentials have been established between the ambientatmospheric pressure and the pressure of the gas in the compartment, andmeans accessible from the exterior of the housing for adjusting therestraining means so as to cause the valve to open in response topredetermined increase in the pressure in the compartment aboveatmospheric pressure.

12. A resuscitator comprising a housing forming a gas receivingcompartment, a diaphragm i'orming one wall of the compartment, means forsealing the margins of the diaphragm to the walls of the housing, theside of the diaphragm opposite the compartment being exposed to ambientatmospheric pressure, the compartment having openings, a fitting on thewall of said housing connecting one oi said openings with a face mask,aspirator means associated with said housing, said aspirator meanshaving a gas inlet and a gas outlet opening into the ambient atmosphere,said asjprator means having an opening forming a spill port andcommunicating with said gas receiving compartment, a movably mountedvalve in said aspirator means downstream from the inlet opening to thespill port, means operated by the diaphragm moving in response tochanges in pressure in said compartment for adiusting cases i l thevalve irom open to closed position and vice versa, means for restrainingthe movement of said last mentioned means preventing adjustment of thevalve i'rom open to closed position and vice versa until predeterminedpressure ditferentials have been established between the ambientatmospheric pressure and the pressure,

of the gas in the compartment, and means messible from the exterior ofthe housing for adjusting the restraining means to cause the valve to"close in response toa predetermined decrease in pressure in thecompartment below atmospheric pressure.

13. A resuscitator comprising a housing forml l a gas receivingcompartment, one wail of the compartment consisting of a movably mounteddiaphragm, the side of the diaphragm opposite the compartment beingexposed to ambient atmospheric pressure, the compartment havingopenings, a fitting on the wall of said housing connecting one of saidopenings with a face mask, aspirator means associated with said housing,said aspirator means having a gas inlet and a gas outlet opening intothe ambient atmosphere, said aspirator means having an opening forming aspill port and communicating with said gas receiving compartment,supporting means carried by the housing, a movably mounted valve in saidaspirator means downstream from the inlet opening to the spill port,means mounted upon the supporting means and operated by the diaphragmmoving in response to changes in pressure in said compartment foradjusting the valve from open to closed position and vice versa, meansfor restraining the movement of said last mentioned means preventingadjustment of the valve from open to closed position and vice versauntil predetermined pressure diilerentials have been established betweenthe ambient atmospheric pressure and the pressure of the gas in thecompartment, and means for adjusting the restraining means to cause thevalve to close in response to a predetermined decrease in pressure inthe compartment below atmospheric pressure.

14. A resuscitator comprising a housing forming a gas receivingcompartment, one wall of the compartment consisting of a movably mounteddiaphragm, the side oi the diaphragm opposite the compartment beingexposed to ambient atmospheric pressure, the compartment havingopenings, a fitting on the wall of said housing connecting one of saidopenings with a face mask, aspirator means associated with said housing,said aspirator means havin a gas inlet and a gas outlet opening into theambient atmosphere, said aspirator means having an opening forming aspill port and communicating with said gas receiving compartment,supporting means carried by the housing, a movably mounted valve in saidaspirator means downstream from the inlet opening to the spill port,means mounted upon the supporting means and operated by the diaphragmmoving in response to changes in pressure in said compartment foradjusting the valve from open to closed position and vice versa, meansfor restraining the movement of said last 'mentioned means preventingadjustment of the valve from open to closed position and vice versauntil predetermined pressure diilercntials have been established betweenthe ambient atmospheric pressure and the pressure oi the gas in thechamber, and means tor adjusting therestrainingmeanssoastocausethevalvetoopenin response to predeterminedincrease in the pres- '12 sure in the compartment above atmosphericpressure.

15. The combination including a gas receiving chamber, a venturi tubeinto which a gas under pressure ilows, said venturi tube having alateral openin communicating with the gas receiving chamber, a valvemounted in the venturi tube downstream from the lateral opening, andmeans for opening and closing the valve so that when the valve is closedthe gas flows into the chamber andwhen open withdraws gas from thechambu, said means including a pressure responsive diaphragm forming onewall of the chamber, a rod connected to the diaphragm, adjustablymounted biasing means for restraining movement of the diaphragm when thevalve is open, and biasing means for restraining the movement of thediaphragm when the valve is closed, and means connected to the rod foractuating the valve to open and closed positions when the pressure ofthe gas overcomes the restraining forces exerted upon the diaphragm.

16. The combination according to claim 15, wherein adjustable means aremounted in the Venturi tube for adjusting the gas inlet passage to theventuri tube for controlling the timing of the operation oi said val 17.The combination including a gas receiving chamber, a Venturi tube intowhich a gas under pressure flows, said venturi tube having a lateralopening communicating with the gas r chamber, a valve mounted in theVenturi tube downstream from the lateral opening, and means for openingand closing the valve so that when the valve is closed the gas flowsinto the chamber and when open withdraws gas from the chamber, saidmeans includin a pressure responsive diaphragm forming one wall oi thechamber, a rod connected to the diaphragm, biasing means for restrainingmovement of the diaphragm when the vaiveis open, and adjustably mountedbiasing means for restrainin the movement of the diaphragm when thevalve is closed, and means connected to the rod for actuating the valveto open and closed positions when the pressure of the gas overcomes therestraining forces exerted upon the diap ragm.

18. The combination including a iluid receiving chamber, pressureresponsive means mounted in one wall of the chamber, which a fluid underpressure ilows, said venturi having a lateral opening communicating withsaid chamber, a valve mounted in the venturi downstream from the lateralopening, means actuated by the pressure responsive means for opening andclosing said valve, so that as the pressure of the fluid in the chamberreaches a predetermined pressure the valve is opened and so that as thepressure in the chamber drops to a predetermined pressure the valve isclosed, and adjustabiy mounted biasing means accessible from theexterior oi the chamber for restraining the movement oi the pressureresponsive means thereby to control the pressures at which the valve isopened and closed.

19. A resuscitator comprising a gas receiving chamber, prasureresponsive means mounted in one wall of the chamber, aspirator meansassociated with said chamber, said aspirator means having a gas inletand a gas outlet opening into the ambient-atmosphere, said aspiratorhaving an opening forming a spill port opening laterally into said gasreceiving chamber, a movably mounted valve in said aspirator means, saidvalve a venturi tube into 98,845 13 14 being located dovrnatream mm thespill port, in the can receiving chamber, the adjustment of valveoperating means ccnneeted to said valve the biasing means ehanrln: saidlimits. and extendin: cntaide of said amiiator Ineanl,

actuating mean! actuated by said pressure rem m me of sponaive mean: toopen and close the valve, and 5 or the original patent adjustable biaainmeans accessible from the 03- UNITED STATES PATENTS terior of thechamber for restraining the movement of the preelure responsive means loa to Number NW Date ml he mnment of the m mum-e 3.536.435 FOX 1951meanawlthinumandlomlimitaofpreaaurea 10'

